Crime scene investigators, law enforcement personnel and private security agents use cameras to photograph crime or incident scenes. The authenticity of these scene photographs typically must be proven and a chain of evidence, i.e. a log of who had access to the photographs and when, established. In other words, the investigator must show that the photograph has not been altered. Traditionally, film cameras have been used because it is difficult to modify a film negative, whereas photographs taken with digital cameras can be easily manipulated using, for example, personal computers.
However, photographs taken with film cameras (or traditional cameras) may not be as convenient as digital photographs. For example, traditional photographs cannot typically be stored in computer files or emailed to others without first scanning them into the computer. Once scanned, they could potentially be manipulated, like digital photos. Thus, scanning the photograph and then saving or emailing it may also not be a valid option as the authenticity of the scanned and/or digital photographs may be questioned and, therefore, may not be admitted as evidence.